The invention relates to a frame structure, especially for erecting seats, such as aircraft passenger seats, on the cabin floor and/or for transport of these seats into and out of the cabin.
Modern aircraft passenger seats as are disclosed, for example, in DE 100 19 484 A1 permit a plurality of movement possibilities and associated degrees of freedom for the individual seat components, such as a seat part, a backrest and an associated leg and foot rest. The known solution is characterized, among other things, in that the actual seat part can be erected on the cabin floor of the aircraft by way of a supporting framework. The supporting framework has a plurality of articulation points, which connect the individual rods of the supporting frame to one another in an articulated manner and accordingly with a capacity to pivot, so that it is possible by way of a suitable control and adjustment means to adjust the entire seat to a plurality of individual positions. For example, it is possible to move the seat from the upright position to a reclining position and vice versa depending on the requirements of the seat occupant and according to given safety criteria. To secure the individual sphere these aircraft passenger seats are often surrounded with a so-called sphere (shell) which also ensures that body parts or articles cannot unintentionally reach the mechanisms of the supporting framework.
To fix the aircraft passenger seats, seat fastening devices, which are also called fittings in the jargon, are used. The fittings are used to fix opposing bottom pairs of legs to longitudinal members of the supporting framework of the seat to mounting rails, which are generally recessed into the cabin floor and are made as a hollow section which is provided on its top facing the passenger seat with a longitudinal channel which is bordered by the free sides of the hollow section and which has through openings which widen its free entry cross section in a definable grid size and which are used for passage of the catch part of a locking body which for relative motion of the respective catch part transversely to the longitudinal axis of the mounting rail can be moved into clamping contact with the sides of the hollow section. Especially advantageously the solution according to DE 10 2004 047 455 A1 uses an eccentric locking drive for this purpose.
In this modular erection concept, each individual seat can optionally be erected with its associated shell part along the mounting rails on the cabin floor and can be fixed in place by means of seat fastening devices, which are described by way of example. If the cabin is to be modified for freight purposes, that is, if the installed seats are to be removed from the cabin or if individual seats have to be replaced due to possible malfunctions or worn seat parts, each individual aircraft passenger seat must be handled in the installation effort. This takes time and therefore generates costs, especially if it is considered that an aircraft out of service cannot generate profits. The known aircraft passenger seat solutions in terms of their basic structure, for example viewed with respect to the supporting framework, can also be made such that they also satisfy increased safety requirements. For example, the seats must withstand a 16 g crash test or, in the torsion of the cabin, which occurs in flight in the longitudinal direction of the aircraft (pitch and roll behavior), the seats must not be adversely affected with regard to stability. If each individual aircraft passenger seat has to be designed according to these criteria, correspondingly high material use is necessary. This leads to increased weight in use and accordingly to a reduction of the profitable payload of the aircraft.